In the lecture videos, Jeremy has mentioned a machine learning course several times as a place to look at for more information. Are these videos currently online? Are these a set of documents somewhere? I can’t seem to find any references on fast.ai to it.
If you can, I highly recommend watching the ML1 videos linked by Simoneva above.
There are shorter than the DL1 (about 1h15m each), less intense and cover some key points of the Fastai library you won’t see in DL1 (Jeremy walks through his code in more details with the ML1 students).